Leap second will be added to this New Year 2017 countdown to requite for a slowdown in the Earth’s rotation.

Extra second will occur when clock strikes midnight time of 23:59:60 will be recorded , delaying the starting of 2017 momentarily.
Last leap second was recorded on June 2015 and now this time occurring of leap time is 27th time.

Change required because standard time lags behind atomic clocks.

Uk national time scale uses atomic clock that provide stable and continuous timescale according to The National Physical Laboratory (NPL) said
It provides the world with its coordinate universal time along with the other clocks across the globe.
Atomic clocks are much better at keeping time than the rotation of the Earth, which fluctuates unpredictably according to NPl senior research scientist Peter Whibberley said
Leap seconds are needed to intercept civil time drifting away from the Earth time

Although because of the drift is small – taking around 1000 years to assemble one hour difference – If not reprove it would finally result in clicks showing midday before sunrise..

Ultraviolet signals that use in the atomic clocks emitted in the change of electron energy levels to tell the time.

GPS location devices used in clocks is used to control the wave frequency of television broadcast.
Earth’s rotation and announcing the need for a leap second track by The International Earth Rotation and Reference Systems Service in France .